One of my favorite humbling moments for him was in the Olympic Mountains of Washington. The 3 of us sauntered to the top of Mt. Ellinor to find a good gathering of Mountain Goats roaming about. We of course put him on his leash and kept him well away from the Goats. More out of respect for their habitat than for his sake. However one of the large momma Goats and her Kid decided they were going to walk right up to Duke and Gina in the middle of a switchback on the trail that backed up against a vertical step of rock. Neither of them had a retreat path. I was quite nervous of what a momma Goat may do to Gina and Duke considering her Kid was right behind her and they were in the way of progress. I was also concerned how Duke may react. Well, as momma approached, Duke backed up, rolled over and showed full submission to the impressive beast encroaching. He knew, this was her terrain and respect was the best tact.
Another time, while visiting my parents in Michigan at my childhood home, my mother in law Barb and I walked him down to the swimming hole of my youth. It was on the Sturgeon River which has steep undercut banks and a swift current. Duke was attempting to drink, catch a fish, see his reflection, something, when he slipped face first into the drink. Unable to get any purchase with his paws and pull himself out, I ran over and yanked him out by the scruff of his neck. He was breathing heavy and completely soaked, but within moments, Duke seamlessly moved onto his next curiosity. A friend who was with us said "He will never forget what you did there, you are now best friends for life." If that's the case, I've pulled him out of more holes than I can remember making us best friends several lifetimes through.